/Engine/Source/Editor/GraphEditor/Public/GraphActionNode.h
Recursively collects all child/grandchild/decendent nodes.
void GetAllNodes ( [TArray](API\Runtime\Core\Containers\TArray)< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FGraphActionNode](API\Editor\GraphEditor\FGraphActionNode) > > & OutNodeArray ) const